From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Date: Sat, 22 Jan 2005 02:53:27 +0000 Subject: Re: Extend clear_page by an order parameter Message-Id: <16881.49191.918994.413281@cargo.ozlabs.ibm.com> List-Id: References: <20050108135636.6796419a.davem@davemloft.net> <16881.33367.660452.55933@cargo.ozlabs.ibm.com> <16881.40893.35593.458777@cargo.ozlabs.ibm.com> <20050121164353.6f205fbc.akpm@osdl.org> <16881.43936.632734.780383@cargo.ozlabs.ibm.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Lameter Cc: Andrew Morton , davem@davemloft.net, hugh@veritas.com, linux-ia64@vger.kernel.org, torvalds@osdl.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Christoph Lameter writes: > I had the name "zero_page" in V1 and V2 of the patch where it was > separate. Then someone complained about code duplication. Well, if you duplicated each arch's clear_page implementation in zero_page, then yes, that would be unnecessary code duplication. I would suggest that for architectures where the clear_page implementation can easily be extended, rename it to clear_page_order (or something) and #define clear_page(x) to be clear_page_order(x, 0). For architectures where it can't, leave clear_page as clear_page and define clear_page_order as an inline function that calls clear_page in a loop. > clear_page is called clear_page because it clears one page of *any* order > not just higher orders. zero-order pages are not segregated nor are they > intrisincally better just because they contain more memory ;-). You have missed my point, which was about address constraints, not a distinction between zero-order pages and higher-order pages. Anyway, I remain of the opinion that your naming is inconsistent with the naming of other functions that deal with zero-order and higher-order pages, such as get_free_pages, alloc_pages, free_pages, etc., and that your patch is unnecessarily intrusive. I guess it's up to Andrew to decide which way we go. Paul.